Trisomy iop. A report of two cases due to a familial translocation rcp (10;21) (pII;pII).

Trisomy for the short arm of chromosome number 10 was diagnosed (by a G-banding method) in two sisters with multiple congenital defects. Their mother and two other sisters showed a balanced translocation 46,XX rcp(10;21)(p11;p11), so the affected girls were the result of a maternal adjacent-1 meiotic segregation with a karyotype 46,XX, der(21), rcp(10;21)(p11;p11)mat. The concordant features in the abnormal patients constitute the following syndrome: severe psychomotor retardation, congenital microsomatia, mild hydrocephalus with cranium-face disproportion, low set ears with hypoplastic helix, ocular colobomata, pulmonary stenosis,flexion deformity of wrists and elbows, bilateral fifth finger clinodactyly and simian creases, hypoplastic dermal ridges, bilateral talipes, persistent icterus and delayed bone age. The phenotypical and cytogenetic findings permit the individualization of the 10p trisomy.